This documentation is archived and is not being maintained.

How to: Specify Client Credentials for a Data Service Request (WCF Data Services)

By default, the client library does not supply credentials when sending a request to an OData service. However, you can specify that credentials be sent to authenticate requests to the data service by supplying a NetworkCredential for the Credentials property of the DataServiceContext. For more information, see Securing WCF Data Services. The example in this topic shows how to explicitly provide credentials that are used by the WCF Data Services client when requesting data from the data service.

The example in this topic uses the Northwind sample data service and autogenerated client data service classes. This service and the client data classes are created when you complete the WCF Data Services quickstart. You can also use the Northwind sample data service that is published on the OData Web site; this sample data service is read-only and attempting to save changes returns an error. The sample data services on the OData Web site allow anonymous authentication.

Example

The following example is from the code-behind page for an Extensible Application Markup Language (XAML) file that is the main page of the Windows Presentation Framework application. This example displays a LoginWindow instance to collect authentication credentials from the user, and then uses these credentials when making a request to the data service.

using System;
using System.Linq;
using System.Net;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Security;
using NorthwindClient.Northwind;
using System.Data.Services.Client;

namespace NorthwindClient
{
    public partial class ClientCredentials : Window
    {
        // Create the binding collections and the data service context.
        private DataServiceCollection<Customer> binding;
        NorthwindEntities context;
        CollectionViewSource customerAddressViewSource;

        // Instantiate the service URI and credentials.
        Uri serviceUri = new Uri("http://localhost:12345/Northwind.svc/");
        NetworkCredential credentials = new NetworkCredential();

        public ClientCredentials()
        {
            InitializeComponent();
        }

        private void ClientCredentials_Loaded(object sender, RoutedEventArgs e)
        {
            string userName = string.Empty;
            string domain = string.Empty;
            SecureString password = new SecureString();

            // Get credentials for authentication.
            LoginWindow login = new LoginWindow();
            login.ShowDialog();

            if (login.DialogResult == true 
                && login.userNameBox.Text != string.Empty
                && login.passwordBox.SecurePassword.Length != 0)
            { 
                // Instantiate the context.
                context =
                    new NorthwindEntities(serviceUri);

                // Get the user name and domain from the login.
                string[] qualifiedUserName = login.userNameBox.Text.Split(new char[] { '\\' });
                if (qualifiedUserName.Length == 2)
                {
                    domain = qualifiedUserName[0];
                    userName = qualifiedUserName[1];
                }
                else
                {
                    userName = login.userNameBox.Text;
                }
                password = login.passwordBox.SecurePassword;

                // Set the client authentication credentials.
                context.Credentials =
                    new NetworkCredential(userName, password, domain);

               
                // Define an anonymous LINQ query that returns a collection of Customer types.
                var query = from c in context.Customers
                            where c.Country == "Germany"
                            select c;

                try
                {
                    // Instantiate the binding collection, which executes the query.
                    binding = new DataServiceCollection<Customer>(query);
         
                    while (binding.Continuation != null)
                    {
                        // Continue to execute the query until all pages are loaded.
                        binding.Load(context.Execute<Customer>(binding.Continuation.NextLinkUri));
                    }

                    // Assign the binding collection to the CollectionViewSource.
                    customerAddressViewSource =
                        (CollectionViewSource)this.Resources["customerViewSource"];
                    customerAddressViewSource.Source = binding;
                }
                catch (Exception ex)
                {
                    MessageBox.Show(ex.Message);
                }
            }
            else if (login.DialogResult == false)
            {
                MessageBox.Show("Login cancelled.");
            }
        }
    }
}

The following XAML defines the main page of the WPF application.

    <Window x:Class="ClientCredentials"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    mc:Ignorable="d"
    d:DesignHeight="312" d:DesignWidth="577" 
             Loaded="ClientCredentials_Loaded">
    <Window.Resources>
        <CollectionViewSource x:Key="customerViewSource" />
    </Window.Resources>
    <Grid x:Name="LayoutRoot" Background="White" DataContext="" Height="312" Width="577"
          VerticalAlignment="Top" HorizontalAlignment="Left">
        <Grid.RowDefinitions>
            <RowDefinition Height="203*" />
            <RowDefinition Height="119*" />
        </Grid.RowDefinitions>
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="336*" />
        </Grid.ColumnDefinitions>
        <DataGrid AutoGenerateColumns="False" Height="213" HorizontalAlignment="Left" 
                      ItemsSource="{Binding Source={StaticResource customerViewSource}}" 
                      Name="customerDataGrid" RowDetailsVisibilityMode="VisibleWhenSelected" 
                      VerticalAlignment="Top" Width="553" Margin="12,44,0,0" 
                      Grid.RowSpan="2" Grid.ColumnSpan="1">
            <DataGrid.Columns>
                <DataGridTextColumn x:Name="customerIDColumn" Binding="{Binding Path=CustomerID}" 
                                        Header="Customer" Width="80" />
                <DataGridTextColumn x:Name="addressColumn" Binding="{Binding Path=Address}" 
                                        Header="Address" Width="180" />
                <DataGridTextColumn x:Name="cityColumn" Binding="{Binding Path=City}" 
                                        Header="City" Width="120" />
                <DataGridTextColumn x:Name="countryColumn" Binding="{Binding Path=Country}" 
                                        Header="Country" Width="80" />
                <DataGridTextColumn x:Name="postalCodeColumn" Binding="{Binding Path=PostalCode}" 
                                        Header="Postal Code" Width="90" />
                <DataGridTextColumn Binding="{Binding Path=CompanyName}" Header="CompanyName" />
                <DataGridTextColumn Binding="{Binding Path=ContactName}" Header="ContactName" />
                <DataGridTextColumn Binding="{Binding Path=Phone}" Header="Phone" />
            </DataGrid.Columns>
        </DataGrid>
        <Label Grid.Row="0" Grid.Column="0" Height="26" HorizontalAlignment="Left" Margin="16,12,0,0" 
                   Name="serviceUriLabel" VerticalAlignment="Top" Width="550"  />
    </Grid>
</Window>

The following example is from the code-behind page for the window that is used to collect the authentication credentials from the user before making a request to the data service.

using System;
using System.Windows;
using System.Windows.Controls;
using System.ComponentModel;

namespace NorthwindClient
{
    public partial class LoginWindow : Window
    {
        public LoginWindow()
        {
            InitializeComponent();
        }

        private void OKButton_Click(object sender, RoutedEventArgs e)
        {
            this.DialogResult = true;
            e.Handled = true;
        }

        private void CancelButton_Click(object sender, RoutedEventArgs e)
        {
             this.DialogResult = false;
             e.Handled = true;
        }

        private void LoginWindow_Closing(object sender, CancelEventArgs e)
        {
            if (this.DialogResult == true &&
                    (this.userNameBox.Text == string.Empty || this.passwordBox.SecurePassword.Length == 0))
            {
                e.Cancel = true;
                MessageBox.Show("Please enter name and password or click Cancel.");
            }
        }

    }
}

The following XAML defines the login of the WPF application.

    <Window x:Class="LoginWindow"
           xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
           xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 
           Width="400" Height="200" 
           Title="LoginWindow" xmlns:sdk="http://schemas.microsoft.com/winfx/2006/xaml/presentation/sdk" Closing="LoginWindow_Closing">
    <StackPanel Name="LayoutRoot" Orientation="Vertical" VerticalAlignment="Top">
        <StackPanel Orientation="Horizontal">
            <TextBlock Height="25" HorizontalAlignment="Left" Margin="10,20,0,0" Name="userNameLabel" VerticalAlignment="Top" 
                       Width="80" Text="User name:"/>
            <TextBox Height="23" HorizontalAlignment="Left" Margin="10,20,0,0"  Name="userNameBox" VerticalAlignment="Top" 
                     Width="150" Text="DOMAIN\login"/>
        </StackPanel>
        <StackPanel Orientation="Horizontal" VerticalAlignment="Top">
            <TextBlock Height="25" HorizontalAlignment="Left" Margin="10,20,0,0" Name="pwdLabel" Width="80" Text="Password:"/>
            <PasswordBox Height="23" HorizontalAlignment="Left" Margin="10,20,0,0" Name="passwordBox" Width="150" />
        </StackPanel>
        <StackPanel Orientation="Horizontal" HorizontalAlignment="Right" Height="80" VerticalAlignment="Top">
            <Button x:Name="CancelButton" Content="Cancel" Click="CancelButton_Click" Width="75" Height="23" 
                HorizontalAlignment="Right" Margin="8" IsCancel="True" />
            <Button x:Name="OKButton" Content="OK" Click="OKButton_Click" Width="75" Height="23" 
                HorizontalAlignment="Right" Margin="8" IsDefault="True" />
        </StackPanel>
    </StackPanel>
</Window>

Security

The following security considerations apply to the example in this topic:

  • To verify that the credentials supplied in this sample work, the Northwind data service must use an authentication scheme other than anonymous access. Otherwise, the Web site hosting the data service will not request credentials.

  • User credentials should only be requested during execution and should not be cached. Credentials must always be stored securely.

  • Data sent with Basic and Digest Authentication is not encrypted, so the data can be seen by an adversary. Additionally, basic authentication credentials (user name and password) are sent in cleartext and can be intercepted.

For more information, see Securing WCF Data Services.

See Also

Show: